As far as I see, people torturing Moscow terrorists on videos are affiliated with Russian neonazi. Probably they're them by themselves.

One of them literally made photo with bloody knife and "black sun" patch for one of Russian far-right telegram channel affiliated with Russian neonazi group (DShRG) "Rusich".

Later another photo of tortures by electricity was published by another Russian nationalist, known by i.e. posting video of Ukrainian soilder decapitation.
This photo was definitely sent by somebody from a police (or who is responsible for prisoners).
(UPD. Looks like it wasn't sent to him by police, he just reposted it from another source unknown for me possibly also far-right.)

So, we can see how Russian far right and neonazi torture people and popularize photo/videos of tortures while Russian government is doing nothing.

And all of that is happening in context of Russia "fighting with Nazis" in Ukraine.

P.S. What do you think this people will do to Ukrainian war prisoners?

P.P.S. Sorry, no source links this time. Those links would be too nsfw.